A FAST AND ACCURATE HIGH PERFORMANCE LIQUID CHROMATOGRAPHY ASSAY TO QUANTIFY PLASMA CEFTAZIDIME CONCENTRATIONS FOR CLINICAL ROUTINE

Abstract

Ceftazidime (C22H22N6O7S2) is a beta-lactam antibiotic. [1,2] It is a bactericidal third-generation cephalosporin, acting on the cell wall by inhibiting the action of carboxipeptidase and transpeptidases and preventing peptidoglycan synthesis and cross-linking, which is necessary for keeping the strength and rigidity of the bacterial cell wall. It presents a broad antibacterial spectrum with higher action on Gram-negative bacteria. Pseudomonas aeruginosa is the pathogen responsible for many nosocomial infections in critically ill patients. Ceftazidime is one of the most active antibiotics against P. aeruginosa. The bactericidal activity of ceftazidime and, in general, beta-lactam antibiotics is time dependent. The pharmacokinetic=pharmacodynamic (PK=PD) index that best correlates with clinical efficacy is the time during which the concentration of antibiotic (in steady state: SS) exceeds the minimum inhibitory concentration (MIC) of the bacteria causing the infection. This index can be expressed as T >MIC > 60 70%. [6] It is also recommended that the SS serum concentration (C) of antibiotic has to be above 4–5 times the MIC for the microorganism. Continuous infusion facilitates to optimize both indices ðT >MIC and C > 4 MICÞ compared to bolus administration or intermittent infusion.